Thomas O'Reilly (ca. 1839 – February 21, 1897) was a trader and political figure in Newfoundland. He represented Placentia and St. Mary's in the Newfoundland and Labrador House of Assembly from 1865 to 1869 as a Conservative.

He was born in Placentia, and later attended St. Bonaventure's College in St. John's, originally returning to Placentia after graduation to work as a teacher.^[1] O'Reilly was defeated when he ran for reelection as a representative in 1869. He served as a magistrate from 1877 until his death in Placentia in 1897.

He founded the local Star of the Sea Society in 1876 and was its president until his death.

A baptism exists in the Freshwater Parish Records for a Thomas of John Reily and Hana Bonia in 1837. This is thought to be his baptism. He was a member of the prominent O'Reilly family of Placentia and the uncle of Archbishop Edward Patrick Roche of St. John's, Newfoundland.

He had nine children, his son William O'Reilly was also a magistrate from 1897 to 1923, and constructed the O'Reilly House museum in which he lived in during his tenure. The museum is a top tourist destination in the Placentia area for anyone looking for history about the area.^[2]